1. Field of the Invention
The present invention relates generally to head suspensions for rigid magnetic disk drives. In particular, the present invention is a lead structure with a stainless steel base which is manufactured separately from and configured for subsequent attachment to the head suspension.
2. Description of the Related Art
Head suspensions for supporting read/write head sliders above the rotating media in magnetic disk drives are in widespread use and disclosed generally in the Christianson et al. U.S. Pat. No. 5,461,525. Head suspensions of this type typically include a stainless steel (spring material) load beam having a mounting region on a proximal end, a rigid region having stiffening rails on its opposite sides, and a radius or spring region between the rigid region and mounting region. A gimbal or flexure is located on the distal end of the load beam. In the embodiment shown in the Christianson et al. Patent, the flexure is manufactured and formed separately from the load beam and subsequently mounted to the load beam. Other types of head suspensions such as those shown in the Blaeser et al. U.S. Pat. No. 5,198,945 include what is known as an integral gimbal which is formed directly on the distal end of the load beam. The mounting region of the head suspension is adapted to be mounted to a rotary actuator in the disk drive, and typically has a base plate welded thereto for added rigidity.
A read/write head slider is mounted, usually by adhesive, to the flexure of the head suspension. The read/write head sliders are commonly electrically connected to electronic circuitry in the disk drive by lead wires. The lead wires are ultrasonically bonded, soldered or otherwise attached to terminals on the read/write head slider and extend along the length of the head suspension to the mounting region. Tabs are often included on the rigid region and mounting region to secure the wire leads to the suspension.
Alternatives to head suspensions with conventional wire leads are known as integrated lead or "wireless" suspensions. A number of different types of integrated lead suspensions are commercially available. One such type of integrated lead suspension is disclosed generally in the Bennin U.S. Pat. No. 5,598,307. The suspension shown in this patent is fabricated from a laminated sheet of material including a stainless steel spring material layer and a copper conductor layer which are bonded together by a dielectric insulating layer. The load beam and flexure are formed from the stainless steel layer by a photolithographic chemical etching process. The integrated leads are formed from the conductor and insulating layers by a similar process.
The Bennin et al. U.S. Pat. No. 5,491,597 discloses a head suspension which is assembled from a load beam and a gimbal-interconnect assembly. The gimbal-interconnect assembly is etched from a layer of conductive spring material, coated with an insulating dielectric and mounted to the load beam.
Another wireless suspension design makes use of a flex circuit mounted to a load beam. The flex circuit structure includes electrical leads encapsulated in a flexible and insulating film. The flex circuit is mounted, typically by adhesive, to the load beam. A flex circuit suspension is disclosed, for example, in PCT Publication No. WO 96/37883.
There remains, however, a continuing need for improved integrated lead suspension technologies. To be commercially viable, any such technology should enable the efficient manufacture of head suspensions having high quality mechanical and electrical characteristics.